Methods of forming microelectronic devices, and related base structures for microelectronic devices

ABSTRACT

A method of forming a microelectronic device comprises forming a source material around substantially an entire periphery of a base material, and removing the source material from lateral sides of the base material while maintaining the source material over an upper surface and a lower surface of the base material. Related methods and base structures for microelectronic devices are also described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No. ______(attorney docket No. 2269-P15363US), filed on even date herewith,listing Kunal R. Parekh as inventor, for “MICROELECTRONIC DEVICES, ANDRELATED METHODS, MEMORY DEVICES, AND ELECTRONIC SYSTEMS.” Thisapplication is also related to U.S. patent application Ser. No. ______(attorney docket No. 2269-P15380US), filed on even date herewith,listing Kunal R. Parekh as inventor, for “METHODS OF FORMINGMICROELECTRONIC DEVICES, AND RELATED MICROELECTRONIC DEVICES, MEMORYDEVICES, ELECTRONIC SYSTEMS, AND ADDITIONAL METHODS.” This applicationis also related to U.S. patent application Ser. No. ______ (attorneydocket No. 2269-P15381US), filed on even date herewith, listing Kunal R.Parekh as inventor, for “METHODS OF FORMING MICROELECTRONIC DEVICES, ANDRELATED MICROELECTRONIC DEVICES AND ELECTRONIC SYSTEMS.” Thisapplication is also related to U.S. patent application Ser. No. ______(attorney docket No. 2269-P15382US), filed on even date herewith,listing Kunal R. Parekh as inventor, for “METHODS OF FORMINGMICROELECTRONIC DEVICES, AND RELATED MICROELECTRONIC DEVICES ANDELECTRONIC SYSTEMS.” This application is also related to U.S. patentapplication Ser. No. ______ (attorney docket No. 2269-P15383US), filedon even date herewith, listing Kunal R. Parekh as inventor, for “METHODSOF FORMING MICROELECTRONIC DEVICES, AND RELATED MICROELECTRONIC DEVICESAND ELECTRONIC SYSTEMS.” The disclosure of each of the foregoingdocuments is hereby incorporated herein in its entirety by reference.

TECHNICAL FIELD

The disclosure, in various embodiments, relates generally to the fieldof microelectronic device design and fabrication. More specifically, thedisclosure relates to methods of forming base structures formicroelectronic devices, methods of forming microelectronic devices, andto related base structures for microelectronic devices.

BACKGROUND

Microelectronic device designers often desire to increase the level ofintegration or density of features within a microelectronic device byreducing the dimensions of the individual features and by reducing theseparation distance between neighboring features. In addition,microelectronic device designers often desire to design architecturesthat are not only compact, but offer performance advantages, as well assimplified designs.

One example of a microelectronic device is a memory device. Memorydevices are generally provided as internal integrated circuits incomputers or other electronic devices. There are many types of memorydevices including, but not limited to, non-volatile memory devices(e.g., NAND Flash memory devices). One way of increasing memory densityin non-volatile memory devices is to utilize vertical memory array (alsoreferred to as a “three-dimensional (3D) memory array”) architectures. Aconventional vertical memory array includes vertical memory stringsextending through openings in one or more decks (e.g., stack structures)including tiers of conductive structures and dielectric materials. Eachvertical memory string may include at least one select device coupled inseries to a serial combination of vertically stacked memory cells. Sucha configuration permits a greater number of switching devices (e.g.,transistors) to be located in a unit of die area (i.e., length and widthof active surface consumed) by building the array upwards (e.g.,vertically) on a die, as compared to structures with conventional planar(e.g., two-dimensional) arrangements of transistors.

Control logic devices within a base control logic structure underlying amemory array of a memory device (e.g., a non-volatile memory device)have been used to control operations (e.g., access operations, readoperations, write operations) of the memory cells of the memory device.An assembly of the control logic devices may be provided in electricalcommunication with the memory cells of the memory array by way ofrouting and interconnect structures. However, processing conditions(e.g., temperatures, pressures, materials) for the formation of thememory array over the base control logic structure can limit theconfigurations and performance of the control logic devices within thebase control logic structure. In addition, the quantities, dimensions,and arrangements of the different control logic devices employed withinthe base control logic structure can also undesirably impede reductionsto the size (e.g., horizontal footprint) of the memory device, and/orimprovements in the performance (e.g., faster memory cell ON/OFF speed,lower threshold switching voltage requirements, faster data transferrates, lower power consumption) of the memory device. Further, as thedensity and complexity of the memory army have increased, so has thecomplexity of the control logic devices. The increased density of thememory array increases the difficulty of forming conductive contactsbetween components of the memory array and components of the controllogic devices.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A through FIG. 1D are simplified cross-sectional viewsillustrating a method of forming a base structure, in accordance withembodiments of the disclosure;

FIG. 2A through FIG. 2C are simplified cross-sectional viewsillustrating a method of forming a base structure, in accordance withother embodiments of the disclosure;

FIG. 3A through FIG. 3C are simplified cross-sectional viewsillustrating a method of forming a base structure, in accordance withadditional embodiments of the disclosure;

FIG. 4A through FIG. 4D are simplified cross-sectional viewsillustrating a method of forming a microelectronic device structureassembly, in accordance with embodiments of the disclosure;

FIG. 5A through FIG. 5C are simplified cross-sectional viewsillustrating a method of forming a microelectronic device structureassembly, in accordance with other embodiments of the disclosure;

FIG. 6A and FIG. 6B are simplified cross-sectional views illustrating amethod of forming a microelectronic device structure assembly, inaccordance with additional embodiments of the disclosure;

FIG. 7 is a block diagram of an electronic system, in accordance withembodiments of the disclosure; and

FIG. 8 is a block diagram of a processor-based system, in accordancewith embodiments of the disclosure.

DETAILED DESCRIPTION

The illustrations included herewith are not meant to be actual views ofany particular systems, microelectronic structures, microelectronicdevices, or integrated circuits thereof, but are merely idealizedrepresentations that are employed to describe embodiments herein.Elements and features common between figures may retain the samenumerical designation except that, for ease of following thedescription, reference numerals begin with the number of the drawing onwhich the elements are introduced or most fully described.

The following description provides specific details, such as materialtypes, material thicknesses, and processing conditions in order toprovide a thorough description of embodiments described herein. However,a person of ordinary skill in the art will understand that theembodiments disclosed herein may be practiced without employing thesespecific details. Indeed, the embodiments may be practiced inconjunction with conventional fabrication techniques employed in thesemiconductor industry. In addition, the description provided hereindoes not form a complete process flow for manufacturing amicroelectronic device (e.g., a semiconductor device, a memory device,such as NAND Flash memory device), apparatus, or electronic system, or acomplete microelectronic device, apparatus, or electronic system. Thestructures described below do not form a complete microelectronicdevice, apparatus, or electronic system. Only those process acts andstructures necessary to understand the embodiments described herein aredescribed in detail below. Additional acts to form a completemicroelectronic device, apparatus, or electronic system from thestructures may be performed by conventional techniques.

The materials described herein may be formed by conventional techniquesincluding, but not limited to, spin coating, blanket coating, chemicalvapor deposition (CVD), atomic layer deposition (ALD), plasma enhancedALD, physical vapor deposition (PVD), plasma enhanced chemical vapordeposition (PECVD), or low pressure chemical vapor deposition (LPCVD).Alternatively, the materials may be grown in situ. Depending on thespecific material to be formed, the technique for depositing or growingthe material may be selected by a person of ordinary skill in the art.The removal of materials may be accomplished by any suitable techniqueincluding, but not limited to, etching, abrasive planarization (e.g.,chemical-mechanical planarization), or other known methods unless thecontext indicates otherwise.

As used herein, the term “configured” refers to a size, shape, materialcomposition, orientation, and arrangement of one or more of at least onestructure and at least one apparatus facilitating operation of one ormore of the structure and the apparatus in a predetermined way.

As used herein, the terms “longitudinal,” “vertical,” “lateral,” and“horizontal” are in reference to a major plane of a substrate (e.g.,base material, base structure, base construction, etc.) in or on whichone or more structures and/or features are formed and are notnecessarily defined by Earth's gravitational field. A “lateral” or“horizontal” direction is a direction that is substantially parallel tothe major plane of the substrate, while a “longitudinal” or “vertical”direction is a direction that is substantially perpendicular to themajor plane of the substrate. The major plane of the substrate isdefined by a surface of the substrate having a relatively large areacompared to other surfaces of the substrate.

As used herein, the term “substantially” in reference to a givenparameter, property, or condition means and includes to a degree thatone of ordinary skill in the art would understand that the givenparameter, property, or condition is met with a degree of variance, suchas within acceptable tolerances. By way of example, depending on theparticular parameter, property, or condition that is substantially met,the parameter, property, or condition may be at least 90.0 percent met,at least 95.0 percent met, at least 99.0 percent met, at least 99.9percent met, or even 100.0 percent met.

As used herein, “about” or “approximately” in reference to a numericalvalue for a particular parameter is inclusive of the numerical value anda degree of variance from the numerical value that one of ordinary skillin the art would understand is within acceptable tolerances for theparticular parameter. For example, “about” or “approximately” inreference to a numerical value may include additional numerical valueswithin a range of from 90.0 percent to 110.0 percent of the numericalvalue, such as within a range of from 95.0 percent to 105.0 percent ofthe numerical value, within a range of from 97.5 percent to 102.5percent of the numerical value, within a range of from 99.0 percent to101.0 percent of the numerical value, within a range of from 99.5percent to 100.5 percent of the numerical value, or within a range offrom 99.9 percent to 100.1 percent of the numerical value.

As used herein, spatially relative terms, such as “beneath,” “below,”“lower,” “bottom,” “above,” “upper,” “top,” “front,” “rear,” “left,”“right,” and the like, may be used for ease of description to describeone element's or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. Unless otherwise specified,the spatially relative terms are intended to encompass differentorientations of the materials in addition to the orientation depicted inthe figures. For example, if materials in the figures are inverted,elements described as “below” or “beneath” or “under” or “on bottom of”other elements or features would then be oriented “above” or “on top of”the other elements or features. Thus, the term “below” can encompassboth an orientation of above and below, depending on the context inwhich the term is used, which will be evident to one of ordinary skillin the art. The materials may be otherwise oriented (e.g., rotated 90degrees, inverted, flipped, etc.) and the spatially relative descriptorsused herein interpreted accordingly.

As used herein, features (e.g., regions, materials, structures, devices)described as “neighboring” one another means and includes features ofthe disclosed identity (or identities) that are located most proximate(e.g., closest to) one another. Additional features (e.g., additionalregions, additional materials, additional structures, additionaldevices) not matching the disclosed identity (or identities) of the“neighboring” features may be disposed between the “neighboring”features. Put another way, the “neighboring” features may be positioneddirectly adjacent one another, such that no other feature intervenesbetween the “neighboring” features; or the “neighboring” features may bepositioned indirectly adjacent one another, such that at least onefeature having an identity other than that associated with at least onethe “neighboring” features is positioned between the “neighboring”features. Accordingly, features described as “vertically neighboring”one another means and includes features of the disclosed identity (oridentities) that are located most vertically proximate (e.g., verticallyclosest to) one another. Moreover, features described as “horizontallyneighboring” one another means and includes features of the disclosedidentity (or identities) that are located most horizontally proximate(e.g., horizontally closest to) one another.

As used herein, the term “memory device” means and includesmicroelectronic devices exhibiting memory functionality, but notnecessary limited to memory functionality. Stated another way, and byway of example only, the term “memory device” means and includes notonly conventional memory (e.g., conventional volatile memory, such asconventional dynamic random access memory (DRAM); conventionalnon-volatile memory, such as conventional NAND memory), but alsoincludes an application specific integrated circuit (ASIC) (e.g., asystem on a chip (SoC)), a microelectronic device combining logic andmemory, and a graphics processing unit (GPU) incorporating memory.

As used herein, “conductive material” means and includes electricallyconductive material such as one or more of a metal (e.g., tungsten (W),titanium (Ti), molybdenum (Mo), niobium (Nb), vanadium (V), hafnium(Hf), tantalum (Ta), chromium (Cr), zirconium (Zr), iron (Fe), ruthenium(Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni),palladium (Pa), platinum (Pt), copper (Cu), silver (Ag), gold (Au),aluminum (Al)), an alloy (e.g., a Co-based alloy, an Fe-based alloy, anNi-based alloy, an Fe- and Ni-based alloy, a Co- and Ni-based alloy, anFe- and Co-based alloy, a Co- and Ni- and Fe-based alloy, an Al-basedalloy, a Cu-based alloy, a magnesium (Mg)-based alloy, a Ti-based alloy,a steel, a low-carbon steel, a stainless steel), a conductivemetal-containing material (e.g., a conductive metal nitride, aconductive metal silicide, a conductive metal carbide, a conductivemetal oxide), and a conductively-doped semiconductor material (e.g.,conductively-doped polysilicon, conductively-doped germanium (Ge),conductively-doped silicon germanium (SiGe)). In addition, a “conductivestructure” means and includes a structure formed of and including aconductive material.

As used herein, “insulative material” means and includes electricallyinsulative material, such one or more of at least one dielectric oxidematerial (e.g., one or more of a silicon oxide (SiO_(x)),phosphosilicate glass, borosilicate glass, borophosphosilicate glass,fluorosilicate glass, an aluminum oxide (AlO_(x)), a hafnium oxide(HfO_(x)), a niobium oxide (NbO_(x)), a titanium oxide (TiO_(x)), azirconium oxide (ZrO_(x)), a tantalum oxide (TaO_(x)), and a magnesiumoxide (MgO_(x))), at least one dielectric nitride material (e.g., asilicon nitride (SiN_(y))), at least one dielectric oxynitride material(e.g., a silicon oxynitride (SiO_(x)N_(y))), and at least one dielectriccarboxynitride material (e.g., a silicon carboxynitride(SiO_(x)C_(z)N_(y))). Formulae including one or more of “x,” “y,” and“z” herein (e.g., SiO_(x), AlO_(x), HfO_(x), NbO_(x), TiO_(x), SiN_(y),SiO_(x)N_(y), SiO_(x)C_(z)N_(y)) represent a material that contains anaverage ratio of “x” atoms of one element, “y” atoms of another element,and “z” atoms of an additional element (if any) for every one atom ofanother element (e.g., Si, Al, Hf, Nb, Ti). As the formulae arerepresentative of relative atomic ratios and not strict chemicalstructure, an insulative material may comprise one or morestoichiometric compounds and/or one or more non-stoichiometriccompounds, and values of “x,” “y,” and “z” (if any) may be integers ormay be non-integers. As used herein, the term “non-stoichiometriccompound” means and includes a chemical compound with an elementalcomposition that cannot be represented by a ratio of well-definednatural numbers and is in violation of the law of definite proportions.In addition, an “insulative structure” means and includes a structureformed of and including an insulative material.

According to embodiments described herein, a method of forming amicroelectronic device comprises forming a first microelectronic devicestructure and attaching the first microelectronic device structure to asecond microelectronic device structure. The first microelectronicdevice structure includes a base structure on which other components(e.g., a memory array, interconnects) are formed. After attaching thefirst microelectronic device structure to the second microelectronicdevice structure, at least a portion of the base structure of the firstmicroelectronic device structure may be removed, such as by grinding,etching, or both. The base structure may include a base materialcomprising, for example, a semiconductive material (e.g., silicon), aceramic material, or a glass material. The base structure may be formedto facilitate removal of the base structure from the firstmicroelectronic device structure after attachment of the firstmicroelectronic device structure to the second microelectronic devicestructure. In some embodiments, the base structure is formed by formingan etch stop material over a surface of the base material, followed byformation of a source material around a periphery of the base structure.The source material may be removed from lateral sides of the basestructure to leave at least a portion of the source material over theetch stop material. Lateral sides of the source material over the etchstop material may be removed and replaced with a protective material(e.g., an oxide material). In other embodiments, the base structurecomprises a doped material over a surface of the base material and aninsulative material over the doped material. Openings may be formedthrough the insulative material to expose the doped material and anepitaxial material may be grown from the doped material to fill theopenings and overlie the insulative material. In yet other embodiments,the base structure comprises a base material comprising a glass materialsurrounded by a source material. The source material may be removed fromlateral sides of the base structure to leave at least a portion of thesource material over base material.

After forming the base structure, additional components (e.g., a memoryarray, interconnects) may be formed over a surface of the base structureto form the first microelectronic device structure. After formation ofthe first microelectronic device structure, the first microelectronicdevice structure may be coupled to a second microelectronic devicestructure to form a microelectronic device structure assembly. Thesecond microelectronic device structure may include a device structureincluding one or more control logic structures for controlling one ormore functions (e.g., operations) of the first microelectronic devicestructure. After attaching the first microelectronic device structure tothe second microelectronic device structure, at least a portion of thebase structure (e.g., the base material) may be removed. After removalof the at least a portion of the base structure, a source structure maybe formed on the first microelectronic device structure (e.g., from thesource material already present on the first microelectronic devicestructure, or from a source material formed on the microelectronicdevice structure assembly). Forming the first microelectronic devicestructure with the base structure may facilitate improved fabrication ofthe microelectronic device structure assembly including the firstmicroelectronic device structure and the second microelectronic devicestructure since the base structure may be fabricated to protect othercomponents of the first microelectronic device structure during backside processing of the first microelectronic device structure, such asduring removal of the base material. For example, the base structure maybe formed to include one or more etch stop materials that may facilitateprotection of the other components of the first microelectronic devicestructure during removal of the base material. In addition, the methodsdescribed herein may facilitate formation and/or patterning of thesource structure of the first microelectronic device structure afterattachment of the first microelectronic device structure to the secondmicroelectronic device structure and removal of the base material.

FIG. 1A through FIG. 1D are simplified partial cross-sectional viewsillustrating embodiments of a method of forming a base structure priorto further processing to form a first microelectronic device structure(e.g., a memory device, such as a 3D NAND Flash memory device). FIG. 1Athrough FIG. 1D illustrate a method of forming a base structure 100 of afirst microelectronic device structure prior to fabrication of, forexample, a memory region on the base structure 100 and prior to bondingof the first microelectronic device structure to a secondmicroelectronic device structure, such as a CMOS substrate.

With the description provided below, it will be readily apparent to oneof ordinary skill in the art that the methods and structures describedherein with reference to FIG. 1A through FIG. 1D may be used in variousdevices and electronic systems.

Referring to FIG. 1A, a base structure 100 (e.g., a first die) maycomprise a base material 102. The base material 102 (e.g.,semiconductive wafer) comprises a material or construction upon whichadditional materials and structures of the base structure 100 areformed. The base material 102 may comprise one or more of semiconductivematerial (e.g., one or more of a silicon material, such monocrystallinesilicon or polycrystalline silicon (also referred to herein as“polysilicon”); silicon-germanium; germanium; gallium arsenide; agallium nitride; gallium phosphide; indium phosphide; indium galliumnitride; and aluminum gallium nitride), a base semiconductive materialon a supporting structure, glass material (e.g., one or more ofborosilicate glass (BSP), phosphosilicate glass (PSG), fluorosilicateglass (FSG), borophosphosilicate glass (BPSG), aluminosilicate glass, analkaline earth boro-aluminosilicate glass, quartz, titania silicateglass, and soda-lime glass), and ceramic material (e.g., one or more ofpoly-aluminum nitride (p-AlN), silicon on poly-aluminum nitride (SOPAN),aluminum nitride (AlN), aluminum oxide (e.g., sapphire; α-Al₂O₃), andsilicon carbide).

In some embodiments, the base material 102 comprises a conventionalsilicon substrate (e.g., a conventional silicon wafer), or another bulksubstrate comprising a semiconductive material. As used herein, the term“bulk substrate” means and includes not only silicon substrates, butalso silicon-on-insulator (SOI) substrates, such as silicon-on-sapphire(SOS) substrates and silicon-on-glass (SOG) substrates, epitaxial layersof silicon on a base semiconductive foundation, and other substratesformed of and including one or more semiconductive materials.

In other embodiments, the base material 102 comprises a glass wafer. Infurther embodiments, the base material 102 comprises a ceramic wafer,such as SOPAN wafer. In some such embodiments, the base material 102 maycomprise a wafer including silicon and a ceramic material.

A thickness (e.g., in the Z-direction) of the base material 102 may begreater than about 500 micrometers (μm), greater than about 750 μm, oreven greater than about 1,000 μm.

With reference to FIG. 1B, an etch stop material 104 may be formed over(e.g., on, directly on) a surface of the base material 102. The etchstop material 104 may include an insulative material exhibiting an etchselectivity with respect to the base material 102. For example, the etchstop material 104 may be formed of and include one or more of silicondioxide, aluminum oxide, hafnium oxide, niobium oxide, titanium oxide,zirconium oxide, tantalum oxide, magnesium oxide, silicon nitride, anoxynitride material (e.g., silicon oxynitride (SiO_(x)N_(y))), and asilicon carboxynitride (SiO_(x)C_(z)N_(y)). In some embodiments, theetch stop material 104 comprises an oxide material, such as silicondioxide. In some embodiments, the etch stop material 104 comprises anoxide of the base material 102. For example, in some embodiments, thebase material 102 comprises silicon and the etch stop material 104comprises silicon dioxide.

The etch stop material 104 may be formed over the surface of the basematerial 102 by one or more of ALD, CVD, PVD, PECVD, LPCVD, or anotherdeposition method. In other embodiments, the etch stop material 104 isformed (e.g., grown) in situ. By way of non-limiting example, the etchstop material 104 may be formed by thermal oxidation, such as byexposing a surface of the base material 102 to oxygen (e.g., O₂, H₂O) ata temperature within a range from about 800° C. to about 1,200° C.

Referring to FIG. 1C, after forming the etch stop material 104, a sourcematerial 106 may be formed around substantially an entire periphery ofthe base structure 100. In other words, the source material 106 mayoverlie and substantially surround the base structure 100. Accordingly,the source material 106 may overlie a major surface of the base material102, a major surface of the etch stop material 104, and sidewalls of thebase material 102 and the etch stop material 104.

The source material 106 may be formed of and include polysilicon. Insome embodiments, the source material 106 is doped with one or moredopants, such as, for example, one or more p-type dopants (e.g., boron,aluminum, gallium, indium), one or more n-type dopants (e.g.,phosphorus, arsenic, antimony, bismuth, lithium), and/or one or moreother dopants (e.g., germanium, silicon, nitrogen).

A thickness (e.g., in the Z-direction) of the source material 106 may bewithin a range from about 50 nanometers (nm) to about 500 nm, such asfrom about 50 nm to about 75 nm, from about 75 nm to about 100 nm, fromabout 100 nm to about 200 nm, from about 200 nm to about 400 nm, or fromabout 400 nm to about 500 nm.

With reference now to FIG. 1D, after forming the source material 106around a periphery of the base structure 100, the source material 106may be removed from lateral sides (e.g., in the X-direction and anotherdirection perpendicular to the X-direction) of the base structure 100.Removal of the source material 106 from lateral sides of the basestructure 100 may expose sidewalls of the base material 102 and the etchstop material 104.

The source material 106 may be removed from the lateral sides of thebase structure 100 by, for example, exposing the base structure 100 toan edge grinding process (also referred to as an edge profiling processor wafer edge grinding), or another edge treatment method. In otherembodiments, the source material 106 is removed by exposing the basestructure 100 to an edge trimming process.

After removing the source material 106 from lateral sides of the basestructure 100, a protective material 108 may be formed on sides of thesource material 106. Accordingly the protective material 108 maysurround lateral sides of the source material 106 located over the etchstop material 104.

The protective material 108 may be formed of and include, for example,one or more of the materials described above with reference to the etchstop material 104. In some embodiments, the protective material 108comprises an oxide material. The protective material 108 may have thesame material composition as the etch stop material 104. In otherembodiments, the protective material 108 has a different materialcomposition than the etch stop material 104. In some embodiments, theprotective material 108 comprises silicon dioxide.

The base structure 100 may be used to facilitate formation of a firstmicroelectronic device structure of a microelectronic device (e.g., asemiconductor device; a memory device, such as a 3D NAND Flash memorydevice). After forming the first microelectronic device structure fromthe base structure 100, the first microelectronic device structure maybe coupled to one or more other microelectronic device structures, suchas a chiplet including one or more control logic regions, as will bedescribed herein.

FIG. 2A through FIG. 2C are simplified partial cross-sectional viewsillustrating embodiments of a method of forming a base structure 200prior to further processing to form a first microelectronic devicestructure of a microelectronic device (e.g., a semiconductor device; amemory device, such as a 3D NAND Flash memory device), in accordancewith additional embodiments of the disclosure. FIG. 2A through FIG. 2Cillustrate a method of forming a base structure 200 prior to fabricationof, for example, a memory array on the base structure 200 to form thefirst microelectronic device structure and prior to bonding the firstmicroelectronic device structure to a second microelectronic devicestructure.

With reference to FIG. 2A, the base structure 200 may include a basematerial 202. The base material 202 comprises a base material orconstruction upon which additional materials and structures of themicroelectronic device structure 200 are formed. The base material 202may include one or more of the materials described above with referenceto the base material 202 (FIG. 1A). For example, the base material 202may comprise one or more of semiconductive material (e.g., one or moreof a silicon material, such monocrystalline silicon or polycrystallinesilicon; silicon-germanium; germanium; gallium arsenide; a galliumnitride; gallium phosphide; indium phosphide; indium gallium nitride;and aluminum gallium nitride) a base semiconductive material on asupporting structure, glass material (e.g., one or more of BSP, PSG,FSG, BPSG, al aluminosilicate glass, an alkaline earthboro-aluminosilicate glass, quartz, titania silicate glass, andsoda-lime glass), and a ceramic material (e.g., one or more of p-AlN,SOPAN, AlN, aluminum oxide (e.g., sapphire; a-Al₂O₃), and siliconcarbide).

In some embodiments, the base material 202 comprises a conventionalsilicon substrate (e.g., a conventional silicon wafer), or another bulksubstrate comprising a semiconductive material. In some embodiments, thebase material 202 comprises a material that may be doped with one ormore dopants.

A thickness (e.g., in the Z-direction) of the base material 202 may bethe same as that described above with reference to the base material102.

With continued reference to FIG. 2A, a doped material 204 may overliethe base material 202. The doped material 204 may include one or moredopants, such as one or more p-type dopants (e.g., boron, aluminum,gallium, indium), one or more n-type dopants (e.g., phosphorus, arsenic,antimony, bismuth, lithium), and/or one or more other dopants (e.g.,germanium, silicon, nitrogen). In some embodiments, the doped material204 comprises the same material composition as the base material 202,except that the doped material 204 is doped with the one or moredopants.

The dopants may be present in the doped material 204 at a concentrationwithin a range from about 1×10¹⁹ atoms/cm³ (or more simply, 1×10¹⁹/cm³)to about 4.0×10²⁰/cm³, such as from about 1×10¹⁹/cm³ to about5×10¹⁹/cm³, from about 5×10¹⁹/cm³ to about 1×10²⁰/cm³, from about1×10²⁰/cm³ to about 2.0×10²⁰/cm³, or from about 2.0×10²⁰/cm³ to about4.0×10²⁰/cm³.

In some embodiments, the doped material 204 comprises one or more ofboron, germanium, and phosphorus. By way of non-limiting example, thedoped material 204 may include silicon doped with boron; silicon dopedwith boron and germanium; silicon doped with phosphorus; or silicondoped with gallium. In some embodiments, the doped material 204comprises so-called heavily boron-doped silicon.

As will be described herein, the doped material 204 may facilitateselective etching of the base material 202 relative to the dopedmaterial 204 during further processing of the base structure 200.Accordingly, the doped material 204 may function as an etch stopmaterial during removal of the base material 202.

An insulative material 206 may overlie the doped material 204. The dopedmaterial 204 may be located between the insulative material 206 and thebase material 202. The insulative material 206 may comprise one or moreof the materials described above with reference to the etch stopmaterial 104 (FIG. 1B). For example, the insulative material 206 may beformed of and include one or more of silicon dioxide, aluminum oxide,hafnium oxide, niobium oxide, titanium oxide, zirconium oxide, tantalumoxide, magnesium oxide, silicon nitride, an oxynitride material (e.g.,silicon oxynitride (SiO_(x)N_(y))), and a silicon carboxynitride(SiO_(x)C_(z)N_(y)). In some embodiments, the insulative material 206comprises silicon dioxide.

Referring to FIG. 2B, the insulative material 206 may be patterned toform openings 208 therein and to expose a portion of the doped material204 through the openings 208. The openings 208 through the insulativematerial 206 may be formed by, for example, exposing the insulativematerial 206 to an etchant through a mask. The insulative material 206may be exposed to a dry etchant comprising one or more of a fluorocarbon(e.g., CH₂F₂, CH₃F, CF₄, C₄Fs, C₄F₆, CF₂), SF₆, NF₃, and oxygen.However, the disclosure is not so limited and the openings 208 throughthe insulative material 206 may be formed by methods other than thosedescribed.

With reference to FIG. 2C, after forming the openings 208 (FIG. 2B) andexposing the doped material 204 through the openings 208, asemiconductive material 210 may be formed over the exposed portions ofthe doped material 204, within the openings 208, and over the remainingportions of the insulative material 206.

In some embodiments, the semiconductive material 210 is formed byepitaxial growth. By way of non-limiting example, the semiconductivematerial 210 may be grown from the exposed portions of the dopedmaterial 204. The semiconductive material 210 may comprise amonocrystalline material and may include a monocrystalline surface 212.In some embodiments, the semiconductive material 210 exhibits the samecrystalline orientation as the doped material 204. The monocrystallinesurface 212 may facilitate formation of one or more device structures onthe monocrystalline surface 212, as will be described herein.

The semiconductive material 210 may be formed of and include one or moreof the materials described above with referenced to the doped material204. In some embodiments, the semiconductive material 210 comprises thesame material composition as the doped material 204, except that aconcentration of the dopants in the semiconductive material 210 is lessthan the concentration of the dopants in the doped material 204. In someembodiments, the semiconductive material 210 comprises doped epitaxialsilicon (e.g., epitaxial silicon doped with one or more of at least onen-type dopant, at least one p-type dopant, or at least another dopant).

The base structure 200 may be used to facilitate formation of a firstmicroelectronic device structure (e.g., a semiconductor device, a memorydevice (e.g., NAND Flash memory device)). After forming the firstmicroelectronic device from the base structure 200, the firstmicroelectronic device may be coupled to one or more othermicroelectronic device structures, such as a chiplet including one ormore control logic regions, as will be described herein.

FIG. 3A through FIG. 3C are simplified partial cross-sectional viewsillustrating embodiments of another method of forming a base structure300, in accordance with embodiments of the disclosure. FIG. 3A throughFIG. 3C illustrate a method of forming a base structure 300 prior tofabrication of, for example, a memory region on the base structure 300to form the first microelectronic device structure and prior to bondingthe first microelectronic device structure to a second microelectronicdevice structure.

With reference to FIG. 3A, the base structure 300 may include a basematerial 302. The base material 302 may include one or more of thematerials described above with reference to the base material 102 (FIG.1A). In some embodiments, the base material 302 comprises a glassmaterial, such as one or more of borosilicate glass (BSP),aluminosilicate glass, an alkaline earth boro-aluminosilicate glass,phosphosilicate glass (PSG), borophosphosilicate glass (BPSG), quartz,titania silicate glass, soda-lime glass.

Referring to FIG. 3B, a source material 304 may be formed aroundsubstantially an entire periphery of the base material 302. The sourcematerial 304 may be formed of and include one or more of the materialsdescribed above with reference to the source material 106 (FIG. 1C). Insome embodiments, the source material 304 comprises polysilicon. In somesuch embodiments, the source material 304 may comprise dopedpolysilicon. The source material 304 may have a same thickness as thesource material 106 described above.

Referring to FIG. 3C, after forming the source material 304, portions ofthe source material 304 on lateral sides of the base material 302 may beremoved, such as by exposing the base structure 300 to an edge grindingprocess, an edge trimming process, or another edge treatment process, asdescribed above with reference to FIG. 1D.

After forming the source material 304, the base structure 300 may beused to facilitate formation of a microelectronic device (e.g., asemiconductor device; a memory device, such as a 3D NAND Flash memorydevice). After forming the first microelectronic device from the basestructure 300, the microelectronic device may be coupled to one or moreother microelectronic device structures, such as a chiplet including oneor more control logic regions, as will be described herein.

As described above, after forming the base structures 100, 200, 300,first microelectronic device structures may be formed on, over, orwithin the base structures 100, 200, 300. The first microelectronicdevice structures may comprise, for example, features (e.g., structures,materials, devices) of a semiconductor device, a memory device (e.g., 3DNAND Flash memory device), or another device. FIG. 4A is a simplifiedcross-sectional view of a first microelectronic device structure 400, inaccordance with embodiments of the disclosure. The first microelectronicdevice structure 400 may also be referred to as an array wafer. Thefirst microelectronic device structure 400 may include an array wafersubstrate 402, which may be substantially similar to the base structure100 described above with reference to FIG. 1D. In other words, the arraywafer substrate 402 may include the base material 102, the etch stopmaterial 104, the source material 106, and the protective material 108.Although the array wafer substrate 402 is illustrated as comprising thebase structure 100, it will be understood that the array wafer substrate402 may be may correspond to any of the base structures 100, 200, 300described above with reference to FIG. 1A through FIG. 3C.

The first microelectronic device structure 400 may be formed to includea memory array region 404 vertically over (e.g., in the Z-direction) thearray wafer substrate 402 and an interconnect region 406 vertically overthe memory array region 404. The memory array region 404 may bevertically interposed between the interconnect region 406 and the arraywafer substrate 402.

The memory array region 404 may include a stack structure 408, linestructures 410 (e.g., digit line structures, bit line structures), andline contact structures 412. The line contact structures 412 mayvertically overlie (e.g., in the Z-direction) the stack structure 408,and may be electrically connected to structures, such as cell pillarstructures 414 and deep contact structures 416 extending through thestack structure 408.

The stack structure 408 may include a vertically alternating (e.g., inthe Z-direction) sequence of conductive structures 418 and insulativestructures 420 arranged in tiers 422. Each of the tiers 422 of the stackstructure 408 may include at least one of the conductive structures 418vertically neighboring at least one of the insulative structures 420. Insome embodiments, the conductive structures 418 are formed of andinclude tungsten and the insulative structures 420 are formed of andinclude silicon dioxide. The conductive structures 418 and insulativestructures 420 of the tiers 422 of the stack structure 408 may eachindividually be substantially planar, and may each individually exhibita desired thickness.

The cell pillar structures 414 may each individually include asemiconductive pillar (e.g., a polysilicon pillar, a silicon-germaniumpillar) at least partially surrounded by one or more charge storagestructures (e.g., a charge trapping structure, such as a charge trappingstructure comprising an oxide-nitride-oxide (“ONO”) material; floatinggate structures). Intersections of the cell pillar structures 414 andthe conductive structures 418 of the tiers 422 of the stack structure408 may define vertically extending strings of memory cells 424 coupledin series with one another within the memory array region 404 of thefirst microelectronic device structure 400. In some embodiments, thememory cells 424 formed at the intersections of the conductivestructures 418 and the cell pillar structures 414 within each the tiers422 of the stack structure 408 comprise so-called “MONOS”(metal-oxide-nitride-oxide-semiconductor) memory cells. In additionalembodiments, the memory cells 424 comprise so-called “TANOS” (tantalumnitride-aluminum oxide-nitride-oxide-semiconductor) memory cells, orso-called “BETANOS” (band/barrier engineered TANOS) memory cells, eachof which are subsets of MONOS memory cells. In further embodiments, thememory cells 424 comprise so-called “floating gate” memory cellsincluding floating gates (e.g., metallic floating gates) as chargestorage structures. The floating gates may horizontally intervenebetween central structures of the cell pillar structures and theconductive structures 418 of the different tiers 422 of the stackstructure 408.

The cell pillar structures 414 may vertically extend from an uppervertical boundary of the stack structure 408, through the stackstructure 408, and to a location at or proximate an upper verticalboundary of the base structure 100 (e.g., within a dielectric materialon the base structure 100).

The deep contact structure(s) 416 may be configured and positioned toelectrically connect one or more components of the first microelectronicdevice structure 400 vertically overlying the stack structure 408 withone or more components of the first microelectronic device structure 400vertically underlying the stack structure 408. The deep contactstructure(s) 416 may be formed of and include conductive material.

With continued reference to FIG. 4A, the interconnect region 406comprises first bond pad structures 426 electrically coupled to the linestructures 410 by first interconnect structures 428. The firstinterconnect structures 428 may vertically overlie (e.g., in theZ-direction) and be electrically connected to the line structures 410and the first bond pad structures 426 may vertically overlie (e.g., inthe Z-direction) and be electrically connected to the first interconnectstructures 428. The first bond pad structures 426 and the firstinterconnect structures 428 may individually be formed of and includeconductive material. In some embodiments, the first bond pad structures426 are formed of and include copper and the first interconnectstructures 428 are formed of and include tungsten.

Referring to FIG. 4B, after forming the memory array region 404 and theinterconnect region 406, the first microelectronic device structure 400may be flipped upside down (e.g., in the Z-direction) and attached(e.g., bonded) to a second microelectronic device structure 460 to forma microelectronic device structure assembly 450 comprising the firstmicroelectronic device structure 400 and the second microelectronicdevice structure 460. The first bond pad structures 426 of theinterconnect region 406 of the first microelectronic device structure400 may be coupled to second bond pad structures 470 of the secondmicroelectronic device structure 460. For example, after flipping thefirst microelectronic device structure 400, the first bond padstructures 426 may be horizontally aligned and brought into physicalcontact with the second bond pad structures 470 of the secondmicroelectronic device structure 460. At least one thermocompressionprocess may be employed to migrate (e.g., diffuse) and interactmaterial(s) (e.g., copper) of the first bond pad structures 426 and thesecond bond pad structures 470 with one another to bond the firstmicroelectronic device structure 400 to the second microelectronicdevice structure 460 to form the microelectronic device structureassembly 450.

The second microelectronic device structure 460 may include a controllogic region 462. The control logic region 462 may include asemiconductive base structure 464, gate structures 466, and routingstructures 468. Portions of the semiconductive base structure 464, gatestructures 466, and routing structures 468 form various control logicdevices of the control logic region 462. The control logic devices maybe configured to control various operations of other components (e.g.,memory cells 424 of the cell pillar structures 414), such as componentsof the first microelectronic device structure 400. The control logicdevices may include devices configured to control read, write, and/orerase operations of the memory cells 424 of the memory cell pillarstructures 414 of the memory array region 404. As a non-limitingexample, the control logic devices may include one or more (e.g., each)of charge pumps (e.g., V_(CCP) charge pumps, VNEGWL charge pumps, DVC2charge pumps), DLL circuitry (e.g., ring oscillators), V_(dd)regulators, string drivers, page buffers, and various chip/deck controlcircuitry. As another non-limiting example, As another non-limitingexample, the control logic devices may include devices to control columnoperations of arrays (e.g., memory element array(s), access devicearray(s)) within the memory array region 404, such as one or more (e.g.,each) of decoders (e.g., local deck decoders, column decoders), senseamplifiers (e.g., EQ amplifiers, ISO amplifiers, NSAs, PSAs), repaircircuitry (e.g., column repair circuitry), I/O devices (e.g., local I/Odevices), memory test devices, MUX, and ECC devices. As a furthernon-limiting example, the control logic devices of the control logicregion 462 may include devices configured to control row operations forarrays (e.g., memory element array(s), access device array(s)) withinthe memory array region 404, such as one or more (e.g., each) ofdecoders (e.g., local deck decoders, row decoders), drivers (e.g., WLdrivers), repair circuitry (e.g., row repair circuitry), memory testdevices, MUX, ECC devices, and self-refresh/wear leveling devices.However, the disclosure is not so limited and the control logic devicesof the control logic region 462 may include other and/or additionalcomponents.

The semiconductive base structure 464 may comprise a base material orconstruction upon which additional materials are formed. Thesemiconductive base structure 464 may comprise a semiconductivestructure (e.g., a semiconductive wafer), or a base semiconductivematerial on a supporting structure. For example, the semiconductive basestructure 464 may comprise a conventional silicon substrate (e.g., aconventional silicon wafer), or another bulk substrate comprising asemiconductive material. In addition, the semiconductive base structure464 may include one or more layers, structures, and/or regions formedtherein and/or thereon. For example, the semiconductive base structure464 may include conductively doped regions and undoped regions. Theconductively doped regions may, for example, be employed as sourceregions and drain regions for transistors of the control logic devicesof the control logic region 462; and the undoped regions may, forexample, be employed as channel regions for the transistors of thecontrol logic devices.

The gate structures 466 of the control logic region 462 may verticallyoverlie (e.g., in the Z-direction) portions of the semiconductive basestructure 464. The gate structures 466 may individually horizontallyextend between and be employed by transistors of the control logicdevices within the control logic region 462 of the secondmicroelectronic device structure 460. The gate structures 466 may beformed of and include a conductive material. A gate dielectric material(e.g., a dielectric oxide) may vertically intervene (e.g., in theZ-direction) between the gate structures 466 and channel regions (e.g.,within the semiconductive base structure 464) of the transistors. Forclarity and ease of understanding of the description, the gatedielectric material is not illustrated in FIG. 4B.

The routing structures 468 may vertically overlie (e.g., in theZ-direction) the semiconductive base structure 464 and may beelectrically connected to the semiconductive base structure 464 by wayof interconnect structures 467. Some of the interconnect structures 467may vertically extend between and electrically couple some of therouting structures 468, and other of the interconnect structures 467 mayvertically extend between and electrically couple regions (e.g.,conductivity doped regions, such as source regions and drain regions) ofthe semiconductive base structure 464 to one or more of the routingstructures 468. The routing structures 468 and the interconnectstructures 467 may each individually be formed of and include conductivematerial.

The second bond pad structures 470 vertically overlie (e.g., in theZ-direction) and electrically connect with the routing structures 468 byone or more interconnect structures. The second bond pad structures 470may be formed of and include conductive material. As described above,the second bond pad structures 470 may be coupled to the first bond padstructures 426 of the first microelectronic device structure 400 to formthe microelectronic device structure assembly 450.

Referring to FIG. 4C, after forming the microelectronic device structureassembly 450, portions of the source material 106 on the back side ofthe base material 102, and the base material 102 may be removed (e.g.,detached) from the first microelectronic device structure 400. Thesource material 106 and the base material 102 may be removed by one ormore material removal processes such as one or both of grinding andetching. For example, the base material 102 may be removed by grindingthe source material 106 and the base material 102. The base material 102may be removed by grinding until a thickness of the base material 102 isless than about 100 μm, such as less than about 75 μm, less than about50 μm, or less than about 40 μm.

After grinding the base material 102, remaining portions of the basematerial 102 may be removed by etching (e.g., wet etching, dry etching)with an etching process selective to the etch stop material 104. As oneexample, the base material 102, may be exposed to a wet etchantcomprising one or both of potassium hydroxide (KOH) andtetramethylammonium hydroxide (TMAH) to selectively remove the basematerial 102 without substantially removing the etch stop material 104.In other embodiments, the base material 102 is exposed to a dry etchingprocess (e.g., reactive ion etching (ME), inductively coupled plasma(ICP) etching) to selectively remove the base material 102 withoutsubstantially removing the etch stop material 104. In some embodiments,the dry etchant includes one or more of sulfur hexafluoride (SF₆),oxygen (O₂), C₄F₈, CF₄, C₃F₆, xenon difluoride (XeF₂), or anothermaterial.

In some embodiments, the presence of the protective material 108 aroundlateral sides of the source material 106 adjacent to the memory arrayregion 404 may protect the source material 106 during removal of thebase material 102. In some embodiments, the protective material 108 mayreduce or substantially prevent contamination of the source material 106with contaminants and particulates generated grinding of the sourcematerial 106 and may also prevent undesired exposure of the sourcematerial 106 to one or more etchants.

With reference to FIG. 4D, after removing the base material 102 (FIG.4B), a back end of the line (BEOL) structure 495 may be formed over theetch stop material 104 and in electrical communication with sourcestructures 480 formed from the source material 106 (FIG. 4C). Forexample, openings may be formed through the etch stop material 104 andthe source material 106 to separate portions of the source material 106from each other and form the source structures 480. The openings may befilled with an insulative material to isolate different portions of thesource structure 480 from each other. The insulative material mayinclude the same material composition as the etch stop material 104. Insome embodiments, a conductive material, such as tungsten silicide(WSi_(X)), tungsten nitride, tungsten silicon nitride (WSi_(x)N_(y)) maybe formed over the source material 106 prior to patterning the sourcematerial 106 to form the source structures 480. In some embodiments, theetch stop material 104 may be removed from surfaces of the sourcematerial 106 prior to forming the conductive material over the sourcematerial 106. In some embodiments, the source structure 480 comprisesone or more of doped silicon (e.g., doped polysilicon), tungstensilicide, tungsten nitride, and tungsten silicon nitride.

The insulative material may isolate portions of the source structure 480in electrical communication with the memory cell pillar structures 414from other portions of the source structure 480 in electricalcommunication with other portions of the memory array region 404 (e.g.,the deep contact structures 416). Since the first microelectronic devicestructure 400 is formed to include the source material 106, the sourcestructures 480 may be formed without deposition of a source materialafter attachment of the first microelectronic device structure 400 tothe second microelectronic device structure 460. In addition, the sourcestructures 480 may be formed without deposition of a source materialafter removal of the base material 102 (FIG. 4B).

The BEOL structure 495 may include second interconnect structures 482 inelectrical communication with the source structures 480 and electricallycoupling the source structures 480 to first metallization structures484. The second interconnect structures 482 may be formed of and includeconductive material, such as tungsten. The first metallizationstructures 484 may be formed of and include conductive material, such ascopper.

Third interconnect structures 486 may electrically couple the firstmetallization structures 484 to second metallization structures 488. Apassivation material 490 may be formed over the microelectronic devicestructure assembly 450 to electrically isolate the second metallizationstructures 488. The third interconnect structures 486 and the secondmetallization structures 488 may be formed of and include conductivematerial. For example, the third interconnect structures 486 may beformed of and include tungsten. The second metallization structures 488may be formed of and include aluminum.

Although FIG. 4A through FIG. 4D have been described and illustrated asincluding the first microelectronic device structure 400 comprising thearray wafer substrate 402 comprising the base structure 100, thedisclosure is not so limited. In other embodiments, the array wafersubstrate 402 comprises the base structure 300 (FIG. 3C). In someembodiments, during removal of the base material 302 (FIG. 3C) from themicroelectronic device structure assembly 450, the base material 302 maybe removed by, for example, exposing the base material 302 tohydrofluoric acid or a grinding process.

In other embodiments, the first microelectronic device structure may beformed with the base structure 200 described above with reference toFIG. 2C. FIG. 5A is a simplified cross-sectional view illustrating amicroelectronic device structure assembly 550 including a firstmicroelectronic device structure 500, in accordance with embodiments ofthe disclosure. The microelectronic device structure assembly 550 issubstantially similar to the microelectronic device structure assembly450 described above with reference to FIG. 4B, except that the firstmicroelectronic device structure 500 includes the base structure 200described above with reference to FIG. 2C. Accordingly, the firstmicroelectronic device structure 500 may include an array wafersubstrate comprising the base structure 200. As described above withreference to FIG. 4A, the memory array region 404 and the interconnectregion 406 may be formed above the array wafer substrate. Thereafter,the first bond pad structures 426 may be bonded to the second bond padstructures 470 of the second microelectronic device structure 460 toform the microelectronic device structure assembly 550.

In some embodiments, the memory array region 404 may be formed over themonocrystalline surface 212 (FIG. 2C) which may facilitate improvedfabrication of the memory array region 404. For example, etching andpatterning of the memory cell pillar structures 414 may be improved byforming the memory cell pillar structures 414 over the monocrystallinesurface 212 compared to conventional microeconomic device structureswherein memory cell pillars are formed polysilicon. In addition, use ofthe base structure 200 may facilitate transfer and attachment of thefirst microelectronic device structure 400 to the second microelectronicdevice structure 460 since the base material 202 may exhibit a greaterstiffness than conventional base materials.

With reference to FIG. 5B, after forming the microelectronic devicestructure assembly 550, at least a portion of the base material 202 ofthe first microelectronic device structure 500 may be removed from themicroelectronic device structure assembly 550. For example, the basematerial 202 may be removed by grinding the base material 202 to athickness less than about 100 μm, such as less than about 75 μm, lessthan about 50 μm, or less than about 40 μm.

After grinding the base material 202, the remaining portions of the basematerial 202 may be removed by one or more material removal processesthat selectively remove the base material 202 relative to the dopedmaterial 204. In other words, the doped material 204 may be used as anetch stop material during removal of the base material 202. By way ofnon-limiting example, base material 202 may be exposed to a wet etchantincluding one or both of KOH and TMAH to remove the remaining portionsof the base material 202 without substantially removing the dopedmaterial 204. In some embodiments, the wet etchant comprises TMAH.Removal of the remaining portions of the base material 202 may exposesurfaces of the doped material 204.

With reference to FIG. 5C, the doped material 204 may be selectivelyremoved relative to the insulative material 206. By way of non-limitingexample, the doped material 204 may be removed with an etchantcomprising nitric acid and hydrofluoric acid. The ratio of thehydrofluoric acid to the nitric acid, the concentration of thehydrofluoric acid and nitric acid, and the temperature of the etchsolution may be controlled to facilitate a desired rate of removal ofthe doped material 204. However, the disclosure is not so limited andthe doped material 204 may be selectively removed relative to theinsulative material 206 by other methods.

After removing the doped material 204, a source structure 580 may beformed over the insulative material 206 and in electrical communicationwith the semiconductive material 210 formed through the insulativematerial 206. The source structure 580 may be substantially similar tothe source structure 480 described above. The source structure 580 maybe formed of and include one or more of doped silicon (e.g., dopedpolysilicon), tungsten silicide, tungsten nitride, and tungsten siliconnitride.

In additional embodiments, the source structure 580 is formed from thedoped material 204. As a non-limiting example, at least partiallydepending on the material composition of the doped material 204,portions of the doped material 204 may be removed (e.g., etched)relative to other portions of the source structure 580 to form thesource structure 580 therefrom. The source structure 580 may correspondto remaining (e.g., unremoved) portions of the doped material 204. Asanother non-limiting example, at least partially depending on thematerial composition and thickness of the doped material 204, the dopedmaterial 204 may be converted into another conductive material andpatterned (e.g., etched) to form the source structure 580.

A thickness (e.g., in the Z-direction) of the source structure 580 maybe within a range from about 50 nm to about 75 nm, from about 75 nm toabout 100 nm, from about 100 nm to about 200 nm, from about 200 nm toabout 400 nm, or from about 400 nm to about 500 nm.

After forming the source structure 580, a back end of the line structure595 may be formed over the source structure 580. For example, secondinterconnect structures 582 may be formed over and in electricalcommunication with the source structure 580. The second interconnectstructures 582 may be formed of and include conductive material, such astungsten. An opening may be formed through the insulative material 206and the source structure 580 to separate portions of the sourcestructure 580 (e.g., portions in electrical communication with thememory cells 424 from portions in electrical communication with the deepcontact structures 416). An insulative material 584 may be formed overthe second interconnect structures 582 and the source structure 580.

First metallization structures 586 may be formed vertically over (e.g.,in the Z-direction) and in electrical communication with the secondinterconnect structures 582. The first metallization structures 586 maybe formed of and include a conductive material, such as copper. Thirdinterconnect structures 588 may be formed over and in electricalcommunication with the first metallization structures 586 andelectrically couple the first metallization structures 586 to secondmetallization structures 592. The third interconnect structures 588 maybe formed of and include a conductive material, such as copper. Thethird metallization structures 590 may be formed of and includeconductive material, such as aluminum. A passivation material may beformed over the microelectronic device structure assembly 550 toelectrically isolate the second metallization structures 592.

Although FIG. 4C and FIG. 5B have been described and illustrated asremoving the base materials 102, 202, 302 by grinding and subsequentetching, the disclosure is not so limited. In other embodiments, thebase materials 102, 202, 302 may be removed based on the crystallineorientation of the base materials 102, 202, 302 and orientationselective etching of the base materials 102, 202, 302 using one or morewet etchants, such as KOH, NaOH, and TMAH. FIG. 6A is a simplifiedcross-sectional view illustrating a microelectronic device structureassembly 650 including a first microelectronic device structure 600attached to a second microelectronic device structure 660. The secondmicroelectronic device structure 660 may be substantially similar to thesecond microelectronic device structure 460 described above withreference to FIG. 4B. The first microelectronic device structure 600 maybe substantially similar any of the first microelectronic devicestructures 400, 500 described above with reference to FIG. 4A throughFIG. 5C. The first microelectronic device structure 600 may be attachedto the second microelectronic device structure 660 as described abovewith reference to attachment of the first microelectronic devicestructures 400, 500 to the second microelectronic device structure 460.

The first microelectronic device structure 600 may include any of thebase structures 100, 200, 300 described above with reference to FIG. 1Athrough FIG. 3C. With reference to FIG. 6A, the first microelectronicdevice structure 600 may include a base material 602 comprising one ormore of the materials described above with reference to the basematerial 102 (FIG. 1A). In some embodiments, the base material 602comprises silicon.

In some embodiments, a protective material 604 may be formed around atleast a portion of the microelectronic device structure assembly 650.For example, the protective material 604 may be disposed around thesecond microelectronic device structure 660. In some embodiments, theprotective material 604 is disposed between the first microelectronicdevice structure 600 and the second microelectronic device structure660, such as in a region 606 between bevels of the first microelectronicdevice structure 600 and the second microelectronic device structure660.

The protective material 604 an insulative material. In some embodiments,the protective material 604 is formed of and includes silicon dioxide.

Referring to FIG. 6B, the base material 602 may be removed (e.g.,detached) from the first microelectronic device structure 600. In someembodiments, the base material 602 is patterned to expose the {100}plane or the {110} plane of the base material 602. The base material 602may be exposed to one or more etchants formulated to remove the basematerial 602 along the {100} plane or the {110} plane, which may formtrenches 608 in the base material 602. In some embodiments, the trenches608 may be patterned with i-line photolithography. In some embodiments,a mask is formed over the base material 602 and slits are formed throughthe mask to expose portions of the base material 602. The base material602 is exposed to the one or more etchants through the openings in themask material. The one or more etchants may include one or both ofpotassium hydroxide and tetramethylammonium hydroxide. In someembodiments, the etchant comprises potassium hydroxide.

After forming the trenches 608, the remaining portions of the basematerial 602 may be removed by exposing the base material to one or moreetchants configured to selectively remove the base material 602 withoutsubstantially removing materials underlying the base material 602 (e.g.,the etch stop material 104 (FIG. 1C), the doped material 204 (FIG. 2C)).The remaining portions of the base material 602 may be selectivelyremoved with respect to materials underlying the base material 602 asdescribed above.

Removing the base material 602 by forming the trenches 608 mayfacilitate improved removal of the base material 602 relative to othermethods of removal of the base material. Since the trenches 608 areformed by i-line photolithography, the trenches 608 may be removed withrelatively low cost methods. In addition, since the base material 602 isremoved based on the orientation of the base material 602, the removalthereof may be at a relatively faster rate than other removal processes.Further, since the base material 602 is not removed by grinding, themicroelectronic device structure assembly 650 may not be exposed toparticles generated from the grinding process.

After removal of the base material 602, a source structure (e.g., thesource structure 580) may be formed over the first microelectronicdevice structure 600, as described above with reference to FIG. 5C.

Although FIG. 4C, FIG. 5B, and FIG. 6B have been described andillustrated as removing the base materials 102, 202, 302, 602 withparticular methods, the disclosure is not so limited. In otherembodiments, the base materials 102, 202, 302, 602 may be formed toinclude hydrogen atoms at a desired depth prior to formation of thememory array region 404 and attachment of the first microelectronicdevice structures 400, 500, 600 to the second microelectronic devicestructures 460, 660. After attachment of the first microelectronicdevice structure 400, 500, 600 to the respective second microelectronicdevice structure 460, 660, the respective base material 102, 202, 302,602 may be removed by fracturing the base material 102, 202, 302, 602 atlocations corresponding to the implanted hydrogen atoms.

Forming the microelectronic device structure assemblies 450, 550, 650according to the methods described herein may facilitate improvedfabrication of microelectronic devices. For example, forming the firstmicroelectronic device structures 400, 500, 600 to include the basestructures 100, 200, 300 prior to attaching the first microelectronicdevice structures 400, 500, 600 to the second microelectronic devicestructure 460 may facilitate improved fabrication of the microelectronicdevice structure assemblies 450, 550, 650. Formation of the basestructures 100, 200, 300 prior to attaching the first microelectronicdevice structures 400, 500, 600 to the second microelectronic devicestructure 460 facilitates formation of the material of the sourcestructure (e.g., the source structure 480, 580) prior to attaching thefirst microelectronic device structures 400, 500, 600 to the secondmicroelectronic device structure 460. In addition, the base structures100, 200, 300 may be fabricated with various materials to facilitateselective removal of the base material 102, 202, 302 after attaching thefirst microelectronic device structures 400, 500, 600 to the secondmicroelectronic device structure 460 and without damaging othercomponents or structures of the respective microelectronic devicestructure assemblies 450, 550, 650. Further, the methods described abovefacilitate fabrication of the second microelectronic device structure460 (e.g., a CMOS wafer including control logic circuitry for one ormore components of the first microelectronic device structures 400, 500,600) separate from the fabrication of the first microelectronic devicestructures 400, 500, 600 (e.g., prior to attaching the firstmicroelectronic device structures 400, 500, 600 to the secondmicroelectronic device structure 460).

Thus, in accordance with some embodiments of the disclosure, a method offorming a microelectronic device comprises forming a source materialaround substantially an entire periphery of a base material, andremoving the source material from lateral sides of the base materialwhile maintaining the source material over an upper surface and a lowersurface of the base material.

Furthermore, in accordance with additional embodiments of thedisclosure, a method of forming a microelectronic device comprisesforming a doped semiconductive material over a base material, forming aninsulative material over the doped semiconductive material, formingopenings in the insulative material and exposing the dopedsemiconductive material through the openings, and epitaxially growingadditional semiconductive material from the doped semiconductivematerial to fill the openings and cover the insulative material.

Moreover, in accordance with further embodiments of the disclosure, abase structure for a microelectronic device comprises a base materialcomprising one or more of a semiconductive material, a ceramic material,and a glass material, and a doped semiconductive material overlying anupper surface of the base material and underlying a lower surface of thebase material, side surfaces of the base material interposed between theupper surface and the lower surface of the base material substantiallyfree of the doped semiconductive material.

In addition, a base structure for a microelectronic device structureaccording to embodiments of the disclosure comprises a base materialcomprising one or more of semiconductive material, ceramic material, andglass material, a doped semiconductive material on the base material, adielectric material on the doped semiconductive material, filledopenings extending through dielectric material to the dopedsemiconductive material, and an epitaxial semiconductive materialsubstantially filling the filled openings and covering surfaces of thedielectric material outside of the filled openings.

In further embodiments, a base structure for a microelectronic devicecomprises a base material comprising one or more of a semiconductivematerial, a ceramic material, and a glass material, doped polysilicon ona first side of the base material and on a second, opposite side of thebase material, and a dielectric material adjacent side surfaces of thedoped polysilicon on one of the first side and the second side of thebase material.

Microelectronic devices including microelectronic device structures(e.g., the first microelectronic device structures 400, 500, 600) andmicroelectronic device structure assemblies (e.g., the microelectronicdevice structure assemblies 450, 550, 650) including the base structures(e.g., the base structures 100, 200, 300) may be used in embodiments ofelectronic systems of the disclosure. For example, FIG. 7 is a blockdiagram of an electronic system 703, in accordance with embodiments ofthe disclosure. The electronic system 703 may comprise, for example, acomputer or computer hardware component, a server or other networkinghardware component, a cellular telephone, a digital camera, a personaldigital assistant (PDA), portable media (e.g., music) player, a Wi-Fi orcellular-enabled tablet such as, for example, an iPAD® or SURFACE®tablet, an electronic book, a navigation device, etc. The electronicsystem 703 includes at least one memory device 705. The memory device705 may include, for example, an embodiment of a microelectronic devicestructure previously described herein (e.g., the first microelectronicdevice structures 400, 500, 600) or a microelectronic device (e.g., themicroelectronic device structure assemblies 450, 550, 650 previouslydescribed with reference to FIG. 4A through FIG. 6B) including theincluding the base structures 100, 200, 300.

The electronic system 703 may further include at least one electronicsignal processor device 707 (often referred to as a “microprocessor”).The electronic signal processor device 707 may, optionally, include anembodiment of a microelectronic device or a microelectronic devicestructure previously described herein (e.g., one or more of the firstmicroelectronic device structures 400, 500, 600 or the microelectronicdevice structure assemblies 450, 550, 650 previously described withreference to FIG. 4A through FIG. 6B). The electronic system 703 mayfurther include one or more input devices 709 for inputting informationinto the electronic system 703 by a user, such as, for example, a mouseor other pointing device, a keyboard, a touchpad, a button, or a controlpanel. The electronic system 703 may further include one or more outputdevices 711 for outputting information (e.g., visual or audio output) toa user such as, for example, a monitor, a display, a printer, an audiooutput jack, a speaker, etc. In some embodiments, the input device 709and the output device 711 may comprise a single touchscreen device thatcan be used both to input information to the electronic system 703 andto output visual information to a user. The input device 709 and theoutput device 711 may communicate electrically with one or more of thememory device 705 and the electronic signal processor device 707.

With reference to FIG. 8, depicted is a processor-based system 800. Theprocessor-based system 800 may include microelectronic device structures(e.g., the first microelectronic device structures 400, 500, 600) andmicroelectronic device structure assemblies (e.g., the microelectronicdevice structure assemblies 450, 550, 650) manufactured in accordancewith embodiments of the present disclosure. The processor-based system800 may be any of a variety of types such as a computer, pager, cellularphone, personal organizer, control circuit, or other electronic device.The processor-based system 800 may include one or more processors 802,such as a microprocessor, to control the processing of system functionsand requests in the processor-based system 800. The processor 802 andother subcomponents of the processor-based system 800 may includemicroelectronic devices and microelectronic device structures (e.g.,microelectronic devices and microelectronic device structures includingone or more of the first microelectronic device structures 400, 500, 600or the microelectronic device structure assemblies 450, 550, 650)manufactured in accordance with embodiments of the present disclosure.

The processor-based system 800 may include a power supply 804 inoperable communication with the processor 802. For example, if theprocessor-based system 800 is a portable system, the power supply 804may include one or more of a fuel cell, a power scavenging device,permanent batteries, replaceable batteries, and rechargeable batteries.The power supply 804 may also include an AC adapter; therefore, theprocessor-based system 800 may be plugged into a wall outlet, forexample. The power supply 804 may also include a DC adapter such thatthe processor-based system 800 may be plugged into a vehicle cigarettelighter or a vehicle power port, for example.

Various other devices may be coupled to the processor 802 depending onthe functions that the processor-based system 800 performs. For example,a user interface 806 may be coupled to the processor 802. The userinterface 806 may include input devices such as buttons, switches, akeyboard, a light pen, a mouse, a digitizer and stylus, a touch screen,a voice recognition system, a microphone, or a combination thereof. Adisplay 808 may also be coupled to the processor 802. The display 808may include an LCD display, an SED display, a CRT display, a DLPdisplay, a plasma display, an OLED display, an LED display, athree-dimensional projection, an audio display, or a combinationthereof. Furthermore, an RF sub-system/baseband processor 810 may alsobe coupled to the processor 802. The RF sub-system/baseband processor810 may include an antenna that is coupled to an RF receiver and to anRF transmitter (not shown). A communication port 812, or more than onecommunication port 812, may also be coupled to the processor 802. Thecommunication port 812 may be adapted to be coupled to one or moreperipheral devices 814, such as a modem, a printer, a computer, ascanner, or a camera, or to a network, such as a local area network,remote area network, intranet, or the Internet, for example.

The processor 802 may control the processor-based system 800 byimplementing software programs stored in the memory. The softwareprograms may include an operating system, database software, draftingsoftware, word processing software, media editing software, or mediaplaying software, for example. The memory is operably coupled to theprocessor 802 to store and facilitate execution of various programs. Forexample, the processor 802 may be coupled to system memory, which mayinclude one or more of spin torque transfer magnetic random accessmemory (STT-MRAM), magnetic random access memory (MRAM), dynamic randomaccess memory (DRAM), static random access memory (SRAM), racetrackmemory, and other known memory types. The system memory 816 may includevolatile memory, non-volatile memory, or a combination thereof. Thesystem memory 816 is typically large so that it can store dynamicallyloaded applications and data. In some embodiments, the system memory 816may include semiconductor devices, such as the microelectronic devicesand microelectronic device structures (e.g., the first microelectronicdevice structures 400, 500, 600 and the microelectronic device structureassemblies 450, 550, 650) described above, or a combination thereof.

The processor 802 may also be coupled to non-volatile memory 818, whichis not to suggest that system memory 816 is necessarily volatile. Thenon-volatile memory 818 may include one or more of STT-MRAM, MRAM,read-only memory (ROM) such as an EPROM, resistive read-only memory(RROM), and flash memory to be used in conjunction with the systemmemory. The size of the non-volatile memory 818 is typically selected tobe just large enough to store any necessary operating system,application programs, and fixed data. Additionally, the non-volatilememory 818 may include a high-capacity memory such as disk drive memory,such as a hybrid-drive including resistive memory or other types ofnon-volatile solid-state memory, for example. The non-volatile memory818 may include microelectronic devices, such as the microelectronicdevices and microelectronic device structures (e.g., the firstmicroelectronic device structures 400, 500, 600 and the microelectronicdevice structure assemblies 450, 550, 650) described above, or acombination thereof.

Accordingly, in at least some embodiments, an electronic systemcomprises an input device, an output device, a processor device operablycoupled to the input device and the output device, and a memory deviceoperably coupled to the processor device and comprising at least onemicroelectronic device structure assembly. The at least onemicroelectronic device structure assembly comprises a firstmicroelectronic device structure comprising a back end of the linestructure comprising metallization materials in electrical communicationwith a source structure, a memory array region comprising strings ofmemory cells extending through a stack structure comprising alternatinglevels of insulative structures and conductive structures, and aninterconnect region including bond pad structures in electricalcommunication with the memory array region. The electronic systemfurther comprises a second microelectronic device structure comprisingCMOS circuitry in electrical communication with the bond pad structures.

While certain illustrative embodiments have been described in connectionwith the figures, those of ordinary skill in the art will recognize andappreciate that embodiments encompassed by the disclosure are notlimited to those embodiments explicitly shown and described herein.Rather, many additions, deletions, and modifications to the embodimentsdescribed herein may be made without departing from the scope ofembodiments encompassed by the disclosure, such as those hereinafterclaimed, including legal equivalents. In addition, features from onedisclosed embodiment may be combined with features of another disclosedembodiment while still being encompassed within the scope of thedisclosure.

What is claimed is:
 1. A method of forming a microelectronic device, themethod comprising: forming a source material around substantially anentire periphery of a base material; and removing the source materialfrom lateral sides of the base material while maintaining the sourcematerial over an upper surface and a lower surface of the base material.2. The method of claim 1, further comprising forming an etch stopmaterial over the base material prior to forming the source materialaround substantially the entire periphery of the base material.
 3. Themethod of claim 2, further comprising: selecting the base material tocomprise a semiconductive material; and selecting the etch stop materialto comprise a dielectric material.
 4. The method of claim 2, furthercomprising: selecting the base material to comprise a silicon; andselecting the etch stop material to comprise silicon dioxide.
 5. Themethod of claim 1, further comprising forming a protective material onlateral sides of remaining portions of source material after removingthe source material from the lateral sides of the base material.
 6. Themethod of claim 1, further comprising selecting the base material tocomprise one or more of monocrystalline silicon, polycrystallinesilicon, silicon-germanium, germanium, gallium arsenide, a galliumnitride, gallium phosphide, indium phosphide, indium gallium nitride,and aluminum gallium nitride.
 7. The method of claim 1, furthercomprising selecting the source material to comprise doped polysilicon.8. The method of claim 1, further comprising selecting the base materialto comprise a ceramic material.
 9. The method of claim 8, whereinselecting the base material to comprise a ceramic material comprisesselecting the base material to comprise silicon on poly-aluminumnitride.
 10. The method of claim 1, further comprising selecting thebase material to comprise a glass material.
 11. The method of claim 10,wherein selecting the base material to comprise a glass materialcomprises selecting the base material to comprise one or more ofborosilicate glass, phosphosilicate glass, fluorosilicate glass,borophosphosilicate glass, aluminosilicate glass, an alkaline earthboro-aluminosilicate glass, quartz, titania silicate glass, andsoda-lime glass.
 12. The method of claim 1, further comprising: forminga stack structure comprising a vertically alternating series ofconductive structures and insulative structures over the sourcematerial; forming vertically extending strings of memory cells withinthe stack structure to form a first microelectronic device structure;attaching the first microelectronic device structure to a secondmicroelectronic device structure comprising control logic circuitry toform a microelectronic device structure assembly; removing the basematerial after forming the microelectronic device structure assembly;and forming circuitry in electrical communication with the sourcematerial after removing the base material.
 13. The method of claim 12,wherein removing the base material comprises one or more of grinding andwet etching the base material.
 14. A method of forming a microelectronicdevice, the method comprising: forming a doped semiconductive materialover a base material; forming an insulative material over the dopedsemiconductive material; forming openings in the insulative material andexposing the doped semiconductive material through the openings; andepitaxially growing additional semiconductive material from the dopedsemiconductive material to fill the openings and cover the insulativematerial.
 15. The method of claim 14, wherein forming a dopedsemiconductive material over a base material comprises forming the dopedsemiconductive material to comprise a semiconductive material of thebase material doped and one or more dopants dispersed within thesemiconductive material.
 16. The method of claim 14, further comprising:forming a stack structure comprising vertically alternating series ofconductive structures and insulative structures over the additionalsemiconductive material; forming vertically extending strings of memorycells within the stack structure to form a first microelectronic devicestructure; coupling the first microelectronic device structure to asecond microelectronic device structure comprising control logiccircuitry to form a microelectronic device structure assembly; andremoving the base material after forming the microelectronic devicestructure assembly.
 17. The method of claim 16, wherein removing thebase material comprises removing the base material without substantiallyremoving the doped semiconductive material.
 18. The method of claim 16,wherein removing the base material comprises forming trenches in thebase material along a {100} plane or a {110} plane of the base material.19. The method of claim 16, further comprising forming a sourcestructure over the additional semiconductive material after removing thebase material.
 20. A base structure for a microelectronic device,comprising: a base material comprising one or more of a semiconductivematerial, a ceramic material, and a glass material; and a dopedsemiconductive material overlying an upper surface of the base materialand underlying a lower surface of the base material, side surfaces ofthe base material interposed between the upper surface and the lowersurface of the base material substantially free of the dopedsemiconductive material.
 21. The base structure of claim 20, furthercomprising a dielectric material interposed between the upper surface ofthe base material and the doped semiconductive material.
 22. The basestructure of claim 21, wherein the doped semiconductive material ispositioned directly adjacent the lower surface of the base material. 23.The base structure of claim 21, further comprising additional dielectricmaterial directly adjacent side surfaces of the doped semiconductivematerial, an uppermost surface of the doped semiconductive materialsubstantially free of the additional dielectric material.
 24. The basestructure of claim 20, wherein the base material comprises asubstantially undoped semiconductive material.
 25. The base structure ofclaim 20, wherein the base material comprises one or more ofborosilicate glass, phosphosilicate glass, fluorosilicate glass,borophosphosilicate glass, aluminosilicate glass, an alkaline earthboro-aluminosilicate glass, quartz, titania silicate glass, andsoda-lime glass.
 26. The base structure of claim 20, wherein the basematerial comprises one or more of poly-aluminum nitride, silicon onpoly-aluminum nitride, aluminum nitride, aluminum oxide, and siliconcarbide.
 27. A base structure for a microelectronic device, comprising:a base material comprising one or more of semiconductive material,ceramic material, and glass material; a doped semiconductive material onthe base material; a dielectric material on the doped semiconductivematerial; filled openings extending through dielectric material to thedoped semiconductive material; and an epitaxial semiconductive materialsubstantially filling the filled openings and covering surfaces of thedielectric material outside of the filled openings.
 28. The basestructure of claim 27, wherein: the base material comprises silicon; thedoped semiconductive material comprises conductively doped silicon; thedielectric material comprises silicon oxide; and the epitaxialsemiconductive material comprises epitaxial silicon.
 29. The basestructure of claim 27, wherein the base material comprises the ceramicmaterial or the glass material.
 30. A base structure for amicroelectronic device, the base structure comprising: a base materialcomprising one or more of a semiconductive material, a ceramic material,and a glass material; doped polysilicon on a first side of the basematerial and on a second, opposite side of the base material; and adielectric material adjacent side surfaces of the doped polysilicon onone of the first side and the second, opposite side of the basematerial.
 31. The base structure of claim 30, wherein a thickness of thedoped polysilicon on the first side of the base material issubstantially the same as a thickness of the doped polysilicon on thesecond, opposite side of the base material.